{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

3-1 CT1 - BENG101 Foundations of Biomedical Imaging Fall...

Info icon This preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon
BENG101 Foundations of Biomedical Imaging Fall 2009 X-ray Computed Tomography (CT) 1
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Introduction X-ray CT produces cross-sectional images representing attenuation of body Tomography – tomos (slice) graphy (writing) Thin x-ray beam scans a set of lines across the field of view, repeated for many angles, yields line attenuation measurements for all angles and distance from the center. This data can be “reconstructed” to yield the attenuation at each point in field of view. Parallel Beam Fan-Beam Geometries Repeated for many angles
Image of page 2
Introduction CT originally CAT (comput(eriz)ed axial tomography), reserved for X-ray CT. Reconstruction from “projection” data formulated by John Radon in 1917. Before this other tomography existed: Linear Tomography Source and Film move at constant speed in opposite directions. Patient plane (P1 – P2) always projected at same point on film, rest of body averaged out. Axial Transverse Tomography Film is horizontal and below focal plane. Patient & film rotate at constant speed, source is fixed. Focal plan stays in focus, other planes are averaged out.
Image of page 3

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
CT History First CT scanner (EMI) developed by Godfrey Hounsfield (1972). Based on math and experiments of Cormack in 1960s. (Shared Nobel prize 1979) First whole-body CT scanner ACTA ( automated, computerized, transverse axial scanner) Ledley in 1974 (Georgetown,DC). ACTA scanner (whole body) EMI scanner (head) Spiral CT (1989) and multislice CT (1998)
Image of page 4
CT Scanner
Image of page 5

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon